WASHINGTON (AP) — The U.S. government has accused Bank of America Corp. of civil fraud, saying the company failed to disclose risks and misled investors in its sale of $850 million of mortgage bonds during 2008.

The Justice Department filed a civil suit Tuesday against the bank and several subsidiaries in federal court in Charlotte, N.C. The Securities and Exchange Commission filed a related suit against Bank of America there, too.

Bank of America disputed the allegations.

The suits accused the second-largest U.S. bank of misleading investors about the risks of the mortgages tied to the securities.

And authorities said the bank of failed to tell investors that more than 70 percent of the mortgages backing the investment were written by mortgage brokers outside the banks’ network. That made the mortgages more vulnerable to default, they said. The bank disclosed the percentage of such mortgage loans in the investment only to a select group of investors, the suits alleged.

Bank of America’s CEO at the time described those mortgages as “toxic waste,” the SEC said.

“Bank of America’s reckless and fraudulent ... practices in the lead-up to the financial crisis caused significant losses to investors,” Anne Tompkins, the U.S. attorney for the Western District of North Carolina, said in a statement. “Now, Bank of America will have to face the consequences of its actions.”

The action was brought by a financial fraud enforcement task force set up to pursue cases related to the 2008 financial crisis.

Bank of America said it will refute the government’s allegations in court.

“These were prime mortgages sold to sophisticated investors who had ample access to the underlying data and we will demonstrate that,” company spokesman Lawrence Grayson said in a statement. “The loans in this pool performed better than loans with similar characteristics (made and packaged into securities) at the same time by other financial institutions.

“We are not responsible for the housing market collapse that caused mortgage loans to default at unprecedented rates and these securities to lose value as a result,” Grayson added.